A wireless local area network (WLAN) technology is a technology based on IEEE 802.11, which can access a backbone network within a radius of about 100 m. In contrast, a WPAN technology is a technology based on IEEE 802.15, which can realize wireless connection between various types of devices within a radius of about 10 m on the basis of personal portable devices, and includes Bluetooth, ZigBee, an ultra wide band (UWB) or the like.
ZigBee refers to IEEE 802.15.4 low-rate wireless personal area networks (LR-WPANs). ZigBee is a communication system which divides a frequency band into three sub-bands, and sets up spreading policies and data rates differently according to the sub-bands. The ZigBee which targets small-sized, low power and low cost products is directing attention from local area communication markets, which provide wireless networking of about 10 m to 20 m distance to houses or offices, and as a key technology for ubiquitous computing that is currently getting popular.
In a broadband wireless access system based on the IEEE 802.16e system, a sleep mode for minimizing power consumption of a mobile station is supported. In the sleep mode, the operation of the mobile station is performed by the repetition of a sleep interval and a listening interval. In the listening interval, the IEEE 802.16e system is used, and, in the sleep interval, the use of other wireless communication such as Bluetooth or WiFi is allowed to provide coexistence of a time sharing scheme.
A beacon signal includes necessary information between communicating identities. In an existence method using a sleep mode, a mobile station may not safely receive beacon signals of another radio access technology (RAT) using a beacon signal, such as WiMedia or ZigBee. That is, since the interval of the beacon signal has various values, a broadband wireless access system uses a predetermined time frame, and a repetition time interval of a sleep period and a reception time interval of the beacon signal are different from each other, the beacon signal may not be safely received in the sleep mode.
Although the broadband wireless access system and WPAN using the beacon signal, such as WiMedia or ZigBee, are implemented in one mobile station, no problem occurs when only one of the broadband wireless access system and the WPAN uses radio resources. However, when the broadband wireless access system and the WPAN simultaneously use same radio resources, a transmission signal of one system may interrupt the reading of a reception signal of the other system. Accordingly, when the broadband wireless access system sends the transmission signal, the mobile station cannot safely receive the beacon signal including important communication-related information used in WiMedia and ZigBee.